As compared with a conventional liquid crystal display panel, an Organic Light Emitting Diode (OLED) display panel has gradually become a mainstream of new generation of flat panel display devices, due to its advantages such as quick response, wide color gamut, ultra-thinness, self-luminescent property, suitable for flexible application and so on.
In order to achieve full-color display of the OLED display panel, a top-emission type White Organic Light Emitting Diode (WOLED) and a Color Filter (CF) layer overlapped on the WOLED are generally employed. Overlapping the color filter layer on a WOLED layer having a plurality of WOLEDs can achieve a high resolution of the OLED display without a masking process using a high-precision metal mask. As shown in FIG. 1, after a thin film transistor (TFT) array substrate 02 comprising the WOLED layer 01 and a package cover plate 04 comprising the color filter layer 03 are respectively formed, a transparent adhesive 05 is provided on a surface of the WOLED layer 01 away from the array substrate 02, then a surface of the package cover plate 04 on which the color filter layer 03 is formed faces the WOLED layer 01, and finally the package cover plate 04 is aligned with and bonded to the array substrate 02 to form the OLED display panel.
However, in the OLED display panel in which the color filter layer 03 is overlapped on the top-emission WOLED layer 01 as shown in FIG. 1, after the package cover plate 04 is bonded with the array substrate 02, the transparent adhesive 05 having a relatively large thickness is provided between the color filter layer 03 and the WOLED layer 01, resulting in a relatively great distance between the color filter layer 03 and the WOLED layer 01; and in this case, because of a self-luminescent property of the WOLED layer 01, when light emitted from a region of the WOLED layer 01 corresponding to a sub-pixel unit of the display panel laterally arrives at the color filter 03, the light may pass through the transparent adhesive 05 to reach color filters of other sub-pixel units. Thus, a color mixture and a color aberration under large viewing angle occur in the OLED display panel; thereby a display effect of the OLED display panel is decreased.